‘s recent gifts to the Bill and Melinda Gates Foundation included $200 million to bring computers, Internet access and training to North American libraries, and $100 million to hasten delivery of vaccines to children in developing countries, said Trevor Neilson, communications director of the foundation. Another high-priority foundation project is the development of a new vaccine to prevent malaria, an initiative to which the Gates‘ donated $50 million, Neilson said. Foundation officials said Gates, the Microsoft Corp . chairman, and his wife have now given more than $5 billion to the foundation in each of the first three quarters of 1999. Gates became the world‘s richest person for the fifth successive year in 1999, Forbes magazine reported in June. Gates‘ net worth blossomed from $51 billion to $90 billion, the magazine said its yearly ranking of the world‘s billionaires.